Urim and Thummim

The Urim and Thummim are named in Exodus as objects placed within the High Priest's breastplate and appear again in Numbers, Deuteronomy and the narrative books, most memorably in the account of Saul consulting them before the battle recorded in First Samuel, yet at no point does the biblical text describe their physical form, only their placement and, in a handful of narrative passages, something of how they were consulted.

Van Dam's monograph, the standard modern study devoted specifically to the subject, works through every occurrence of the pair across the Hebrew Bible and concludes that the text simply never intended to specify their appearance, treating their use as familiar enough to its original audience that no description was thought necessary, a gap modern readers experience very differently than the text's first readers evidently did.

Proposed reconstructions across the long history of Jewish and Christian commentary have ranged from a pair of engraved stones or lots read as a form of binary yes or no answer, to a more elaborate mechanism involving the breastplate's twelve tribal stones, and no single proposal has ever achieved anything close to full scholarly consensus.

Narrative use of the Urim and Thummim clusters in the period of the Judges and the early monarchy, when figures including Saul and David are described consulting them, usually through the High Priest, for guidance on specific practical questions, most often military ones, functioning as a recognised institutional channel of divine guidance distinct from prophecy. Their consultation appears to fall away as a recorded practice well before the end of the First Temple period, and later biblical and post biblical Jewish tradition, including passages in Ezra reflecting on priests unable to determine certain matters until a priest should arise who could consult Urim and Thummim, treats the practice as already unavailable by the return from Babylonian exile.

Rabbinic tradition subsequently held that the Urim and Thummim, along with several other specific gifts, ceased to function with the end of the First Temple and the classical era of prophecy, and Van Dam's study treats this rabbinic reckoning as broadly consistent with what the biblical text itself implies, an institution whose active use is confined to a specific, comparatively early window of Israelite religious history rather than one that continued unbroken into the Second Temple period the surviving priestly breastplate tradition otherwise describes.